1. Field of the Invention
The present invention generally relates to a process for manufacturing deep trench capacitors and more particularly to an improved etching process that etches titanium nitride trench conductors more effectively than conventional manufacturing methods.
2. Description of the Related Art
In the state of the art semiconductor manufacturing, trench capacitors may be formed to store electrical charge. As the miniaturization of the semiconductor devices progresses, the feature size of the storage trench has correspondingly shrunk. State of the art memory devices today use trenches with opening sizes of less than 120 nm. A large amount of charge must be placed into each trench to compensate for charge leakage out of these trenches. Thus, the retention time of the memory device scales with the total current stored in each trench. Since the opening dimension of these trenches reduces with feature size, the available storage area has historically been increased by increasing the depth of the trench into single crystal silicon. Current state of the art devices require trench depths of 7.5 μm to allow for adequate charge storage.